Question

Mr. Abernathy purchased a selection of wrenches for his shop. The total cost was $78. He bought the same number of $1.50 and $2.50 wrenches, and half that many $4 wrenches. The number of $3 wrenches was one more than the number of $4 wrenches. How many of each did he purchase?

Answer 1

78 = 1.50x + 2.50x + 4(x/2)) + 3((x/2) + 1))
78 = 4x + 4(x/2) + 3((x/2)+1)
78 = 4x + 2x + (3(x/2) + 3)
78 = 6x + 1.5x + 3
75 = 7.5x
10 = x
Mr. Abernathy bought 10 wrenches at $1.50, 10 wrenches at $2.50, 5 wrenches at $4, and 6 wrenches at $3.